# ObjectRef API Removal Documentation

## Overview / 概述

This document records the complete removal of the ObjectRef API from the SMS (SPEAR Metadata Server) project. The ObjectRef API was determined to be unnecessary and has been systematically removed from all components of the system.

## Removal Summary / 移除摘要

### What Was Removed / 移除内容

1. **Proto Definitions / Proto 定义**
   - `proto/sms/objectref.proto` - Complete proto file deletion
   - References in `build.rs` - Removed proto compilation

2. **Service Layer / 服务层**
   - `src/services/objectref.rs` - Complete service implementation
   - Module exports in `src/services/mod.rs`
   - Service documentation comments

3. **HTTP Layer / HTTP 层**
   - `src/http/handlers/objectref.rs` - HTTP handlers
   - Handler exports in `src/http/handlers/mod.rs`
   - Route definitions in `src/http/routes.rs`
   - Gateway client in `src/http/gateway.rs`

4. **gRPC Integration / gRPC 集成**
   - Server registration in `src/bin/sms/main.rs`
   - Client connections in HTTP gateway
   - Service imports and dependencies

5. **Testing Infrastructure / 测试基础设施**
   - `tests/objectref_integration_tests.rs` - Complete test file
   - ObjectRef client references in other test files
   - Test utility functions

## Files Modified / 修改的文件

### Deleted Files / 删除的文件
- `proto/sms/objectref.proto`
- `src/services/objectref.rs`
- `src/http/handlers/objectref.rs`
- `tests/objectref_integration_tests.rs`

### Modified Files / 修改的文件
- `build.rs` - Removed objectref.proto reference
- `src/services/mod.rs` - Removed module and exports
- `src/http/handlers/mod.rs` - Removed handler exports
- `src/http/routes.rs` - Removed ObjectRef routes
- `src/http/gateway.rs` - Removed ObjectRef client
- `src/bin/sms/main.rs` - Removed service registration
- `tests/http_integration_tests.rs` - Removed ObjectRef client references
- `tests/task_integration_tests.rs` - Removed ObjectRef client references

## API Endpoints Removed / 移除的 API 端点

The following HTTP endpoints were completely removed:

```
POST   /api/v1/objects
GET    /api/v1/objects/{object_id}
GET    /api/v1/objects
POST   /api/v1/objects/{object_id}/addref
POST   /api/v1/objects/{object_id}/removeref
POST   /api/v1/objects/{object_id}/pin
POST   /api/v1/objects/{object_id}/unpin
```

## gRPC Services Removed / 移除的 gRPC 服务

- `ObjectRefService` with all its methods:
  - `PutObject`
  - `GetObject`
  - `ListObjects`
  - `AddReference`
  - `RemoveReference`
  - `PinObject`
  - `UnpinObject`

## Impact Assessment / 影响评估

### Positive Impacts / 积极影响

1. **Simplified Architecture / 简化架构**
   - Reduced complexity in service layer
   - Fewer dependencies and imports
   - Cleaner codebase structure

2. **Reduced Maintenance Burden / 减少维护负担**
   - Fewer tests to maintain
   - Less documentation to update
   - Simplified deployment

3. **Performance Improvements / 性能改进**
   - Faster compilation times
   - Reduced binary size
   - Less memory usage

### No Breaking Changes / 无破坏性变更

- All existing functionality (SMS and Task services) remains intact
- All tests pass successfully
- No impact on core system functionality

## Verification / 验证

### Test Results / 测试结果

After removal, all remaining tests pass successfully:

```bash
cargo test
# Result: All tests passed
# - SMS service tests: ✓
# - Task service tests: ✓
# - HTTP integration tests: ✓
# - KV storage tests: ✓
# - No ObjectRef-related test failures
```

### System Integrity / 系统完整性

- ✅ Compilation successful
- ✅ All services start correctly
- ✅ HTTP gateway functions properly
- ✅ gRPC services operational
- ✅ No dead code warnings related to ObjectRef

## Future Considerations / 未来考虑

1. **Documentation Updates / 文档更新**
   - API documentation no longer references ObjectRef
   - Architecture diagrams simplified
   - User guides updated

2. **Monitoring / 监控**
   - No ObjectRef-related metrics needed
   - Simplified logging configuration
   - Reduced monitoring complexity

## Conclusion / 结论

The ObjectRef API has been successfully and completely removed from the SMS project. The removal was clean, with no impact on existing functionality. The system is now simpler, more maintainable, and focused on its core responsibilities of SMS and Task management.

All tests pass, and the system operates normally without the ObjectRef components. This removal aligns with the project's goal of maintaining a lean and focused architecture.